1. Field of the Invention
The invention relates to an improvement of a disease judging apparatus that examines and diagnoses Alzheimer's disease and the like by measuring areas of the pupils of a subject.
2. Related Art
It has recently been revealed that whether or not a subject is affected with Alzheimer's disease can be diagnosed by dropping a pupil dilating dilution into an eye of the subject, measuring the diameter (area) of the pupil of the eye, and calculating the magnification after dropping the pupil dilating dilution (a U.S. periodical "SCIENCE" (VOL. 266, Nov. 11, 1994)). A method therefor involves the steps of: dropping a pupil dilating dilution into, e.g., the left eye of a subject and a physiological saline to the right eye; measuring the magnification of the pupil area for a time period lasting for 30 to 60 minutes thereafter; and judging whether or not the subject has contracted Alzheimer's disease from the calculated magnification.
Further, eyedrop tests in which a special eyedrops is applied to a subject in order to check that the subject suffers from autonomic unbalance have heretofore been conducted. In these eyedrops tests, a pupil is photographed before and after the eyedrops have been dropped, and the size of the pupil of the left eye and that of the right eye are measured using a ruler and compared with one another.
For example, an apparatus according to the prior art which is based on a pupil dilating dilution dropping method measures the area of the pupil of the right eye into which the physiological saline has been dropped, but such measured value is used only for reference. That is, when the apparatus according to the prior art judges whether or not a subject has contracted Alzheimer's disease, it is only the magnification of the left eye into which the pupil dilating dilution has been dropped that is used as an index value. Further, in order to judge whether or not a subject suffers from autonomic unbalance, it is only the magnification of the pupil of the left eye into which a special eyedrops (1.25% epinephrine, 5% tyramine, 5% cocaine, etc.) has been dropped that is measured.
A pupil expands widely in a dark place and contracts in a well-lighted place. Further, a pupil dilates and contracts due to influences derived from an autonomic nerve phyletic line. For example, when a person is surprised, his or her pupils dilate widely. Therefore, the magnification of the pupil area measured by the apparatus according to the prior art is such influenced data, and is, hence, not considered a genuine magnification that is derived only from the dropping of the eyedrops. As a result, it has been difficult to make a correct judgment on whether or not a subject suffers from Alzheimer's disease or autonomic unbalance.